Class: BulldogPhysics::Spring
- Inherits:
-
ForceGenerator
- Object
- ForceGenerator
- BulldogPhysics::Spring
- Defined in:
- lib/RigidBodies/spring.rb
Instance Attribute Summary collapse
-
#connection_point ⇒ Object
readonly
connection point in local coords.
-
#other ⇒ Object
readonly
particle at the other end of the spring.
-
#other_connection_point ⇒ Object
readonly
point of connection of the spring to the other object in that objects local coords.
-
#rest_length ⇒ Object
readonly
Returns the value of attribute rest_length.
-
#spring_constant ⇒ Object
readonly
Returns the value of attribute spring_constant.
Instance Method Summary collapse
-
#initialize(local_connection_pt, other_body, other_connection_point, spring_constant, rest_length) ⇒ Spring
constructor
A new instance of Spring.
- #update_force(body, duration) ⇒ Object
Constructor Details
#initialize(local_connection_pt, other_body, other_connection_point, spring_constant, rest_length) ⇒ Spring
Returns a new instance of Spring.
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# File 'lib/RigidBodies/spring.rb', line 11 def initialize(local_connection_pt, other_body, other_connection_point, spring_constant, rest_length) @conection_point, @other, @other_connection_point, @spring_constant, @rest_length = local_connection_pt, other_body, other_connection_point, spring_constant, rest_length end |
Instance Attribute Details
#connection_point ⇒ Object (readonly)
connection point in local coords
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# File 'lib/RigidBodies/spring.rb', line 5 def connection_point @connection_point end |
#other ⇒ Object (readonly)
particle at the other end of the spring
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# File 'lib/RigidBodies/spring.rb', line 7 def other @other end |
#other_connection_point ⇒ Object (readonly)
point of connection of the spring to the other object in that objects local coords
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# File 'lib/RigidBodies/spring.rb', line 6 def other_connection_point @other_connection_point end |
#rest_length ⇒ Object (readonly)
Returns the value of attribute rest_length.
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# File 'lib/RigidBodies/spring.rb', line 9 def rest_length @rest_length end |
#spring_constant ⇒ Object (readonly)
Returns the value of attribute spring_constant.
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# File 'lib/RigidBodies/spring.rb', line 8 def spring_constant @spring_constant end |
Instance Method Details
#update_force(body, duration) ⇒ Object
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# File 'lib/RigidBodies/spring.rb', line 15 def update_force(body, duration) # calc ends in world space lws = body.get_point_in_world_space(@conection_point) ows = other.get_point_in_world_space(@other_connection_point) # calculate the vector of the string force = lws - ows # calculate magnitude of the force magnitude = force.magnitude magnitude = (magnitude - @rest_length).abs magnitude *= @spring_constant # calculate and apply the final force force.normalize force *= -magnitude body.add_force_at_point(force, lws) end |